Telescoping Trailer Tongue Extension Question

[adamis]

I currently have a 12 foot cargo trailer and I'm looking at purchasing a 26 foot travel trailer both of which will be towed by my truck with camper for business purposes (one at a time of course). I've considered having a local welding shop modify the tongues of both trailers to have a telescoping trailer tongue that can be extended / retracted depending on whether I have the camper on the truck or not. I already have a super truss hitch extension in place but I'm thinking that having the ability to extend the trailer tongue as needed will be more convenient for my use then having to add and remove the super truss. Doing a quick google search seems to be turning up a few results that look interesting.

On my Bigfoot 10.6E Camper it does extend past the bed of the truck by ~3ft but it does not drop below the height of the bed. I think I should have plenty of clearance for when the truck and trailer are at extreme angles to each other. Most of my time I'll be on pavement anyway and about the most extreme angles I'll likely encounter are driveway entrances and speed bumps.

I think I would need about 3ft of telescoping tongue to fit my needs. Does anyone have any experience with such a setup?

I found an example of someone doing this type of work here:

[Grit_dog]

And for those worried about a press fit on the telescope part, not to worry.
There are much sloppier setups than that that function fine.
I've had a couple fold away hitches, one I had to beef up cause it was a home made job that walleyed out the pin holes. Even after that it had some slop up n down. Lots of miles later it was perfectly serviceable, just another clunk going over bumps.

[Grit_dog]

@burningman, those dump trailer hatches you're talking about on truck n pup setups are not weight carrying, so completely different application.
However, the telescoping hitch can/will work fine if fabbed right.
But, first check out simple shorter hitch extensions. May not be your answer, but if the camper has zero vertical overhang you may not need as long an extension depending how your trailers fit up to the truck.
As said vertical clearance will be no issue.
My AF hangs out 3' plus past the back of the bed if you include the bumper step.
I've hauled a number of trailers with a 12" hitch extension and nothing more. I don't have my full tight turning radius with the boat because it's a pickle fork front end and I could jackknife others into the camp r if I tried....but most conditions it's fine and I pack a longer extension in case I get into a tight spot and need to jackknife the trailer out. Haven't had to use it yet.
May be a simple cheaper solution since you already have a beefy hitch that will handle extensions with ease.

[HMS_Beagle]

Put simply, extending the hitch on your truck with a given trailer tongue weight will transfer more weight from the front axle to the rear axle of the truck in proportion to the extension. Alternatively, extending the tongue will transfer more weight from the tongue to the trailer axle, reducing tongue weight on the truck hitch.

Reducing tongue weight while leaving everything else the same on a trailer may affect its dynamics negatively, however reducing tongue weight by extending the tongue is most likely to improve the dynamics (unless you make it too floppy).

[towpro]

think about this.
I currently have an object that is 19' long and weighs 5000 lbs.

1) The center of gravity. for this load is is 9' back from front.
2) There is a pivot point 10' back from front. (axle)
a) This pivot point is 10% behind the center of gravity.
b)In Theory to lift the front of weight, since its 10% more weight forward on pivot location, it would take 500 lbs (10% of 5000 lbs) of force to lift it (tong weight)

4) now if I extended a leaver on front of this weight, out 5' (50% more), would it still take 500 lbs of force to lift the front of this weight, or 500 lbs - 50% leaver = 250 lbs?
I mean your fulcrum is still the axle, but we just added a longer leaver (hitch extension)

I don't think hitch length extension is multiplying weight, I think its reducing it?


but now if I put a 5' leaver out of back of truck, that is fixed to truck, with center of truck as axis,
and have a pivot point where it connects to the front of this 500 lb weigh, (like a truss or hitch extension) that will multiply the 500 lb weight that is on the pivot end

[Boatycall]

I purchased a 12' utility trailer from Costco something like 10+ years ago, and it came set up virtually identical to this, with an extendable tongue.
Granted, it's only a 2500lb trailer, but I've never had a problem with it.

adamis wrote:

I found an example of someone doing this type of work here:

[HMS_Beagle]

One pin and a safety chain makes it identical to a receiver hitch. Two bolts is what holds many couplers to their trailers. Either could be used without sacrificing strength or safety. There is little extra bending moment on the trailer frame as you extend the tongue. Much more on the receiver as you extend it. This stuff is easily engineered and built to be as strong as it was before. Not with bubble gum and chicken wire, but pretty easy with a calculator and a MIG welder. You have to engineer it, you can't just bungie a 2x4 on there and go, but it is far from rocket science.

[adamis]

I want to clarify that the pictures I've shown in my initial post are just an example of the idea. The modifications I might make to my own trailer will incorporate much larger box tubing for more strength. I will also incorporate at least two pins in addition to chains or cables extending from the tongue to the trailer with tension for added stability and strength.

I appreciate everyone's input so far. I'll be taking the thoughts and suggestions in mind as I meet with a local welding shop in a week or two that specializes in trailers to see what they say and will report back.

[stevenal]

The problem I see with a telescoping tongue is that it will be changing the tongue weight when moved from one position to another. Long tongues, removable tongues, and foldable tongues don't have this problem; since you would set them up for proper tongue weight for the traveling position.

[jimh406]

It doesn't look like the person who built their telescoping extension is extending 3 ft.

Truck hitches are derated when you use an extension. Extending a trailer tongue either permanently or temporarily will have a similar effect. I'm making the assumption that there is a reason why heavier load trailers are reinforced from the frame to the tongue.

Sounds creative, but physics wise, I think you will produce new leverage forces that weren't considered when the trailer was designed.

[finsruskw]

If this was such a good idea, one would think it would be an option with trailer Mfgr's.

Also, any homemade setup would incur mountains of liability issues should, God forbid, anything were to happen.

That's why went w/all new torklift gear on my rig when I bought it.
Good luck w/your plan of action.

[ticki2]

Aside from the engineering of the sizes of material for the weights involved the principle is the same as the ball shank in the receiver . It's a single hitch pin with safety chains . Many boat trailers use something similar where the tongue shaft can hinge ( on a bolt )to drop the rear of the trailer for loading . The OP picture shows a standard 2" tube which I don't think would be adequate for a 5000# TT .

[mkirsch]

Ok, whatever. Make it out of bubble gum and rubber bands. It'll be fine.

In the first pictures, what is keeping the tongue extension from sliding out and the trailer from sailing off into the sunset if that pin breaks? NOTHING. And that will pass a safety inspection? I doubt it.

[HMS_Beagle]

Of course this can be done.

There is very little difference in engineering the extension on the trailer vs. the truck. There is no difference in safety, if equally engineered - as mentioned above, a receiver hitch is already a telescoping joint, and telescoping joints are common on trailers with surge brakes. The geometry of trailer towing is improved the closer to the rear axle the ball gets which will improve safety and handling. Interference between trailer box and camper will be less likely with an extended tongue than an extended hitch. If the tongue hits the bottom of a Bigfoot you are way further off road than you should be with that rig. The only negative in the idea is you have to do it for each trailer rather than once for the truck, and it is not the well worn path so you will have to deal with all the nay sayers.

One negative not mentioned is it makes hitching and unhitching a bit more difficult, you have to crawl in the dirt to get to the hitch, chains, plugs, etc.

[towpro]

as someone that still has there PA state Inspection for inspecting trailers (even over 10K lbs) I would have no problem with what is shown in the first picture. welds look good from what I can see. Maybe a plate under the Front edge where the "A" comes to center plate would give you more strength, that appears to be where the trailer weight is transferred into tong weight. I am not a (good) welder so maybe the plate is not needed.

and I would not be worried about it being "tight". Ever seen those single axle drive on trailer? same concept where the tong goes back almost to axle, and whole bed flips up while tong is still attached to vehicle. when bed is down it might provide some left to right support but not much.

as far as using that CURT extension to make your telescopic trailer, that extension has a bend to it and I don't think your internal 2" would slide in that far.

But no fear, any metal shop that makes stuff should have the 2 different size tubes you need, pre measure and they will even make a nice cut in it for you. out my way they Amish metal shop might even charge me $1.00 per hole to pre drill it.


I would not worry about making it tight. its the same fit as your hitch sliding into your truck receiver. It will not clunk any worse than your hitch does.
in fact since the bearing surface between the two is so long it might make less noise than your current hitch.

but I would run safety chains to the main trailer A frame parts, along with break away switch.

[Reality_Check]

mkirsch wrote:
You guys missed one thing:

He wants a TELESCOPING tongue, not just an extended tongue.

I'm not sure such a thing is even legal. You'd have to check state laws on trailer construction.

For sure you'd need at least two ways to lock the tongue in position. It would be counterproductive to have a lone locking pin fall out or fail in a hard stop, sending the trailer into the rear of the camper.

For sure you'd want the slip fit to be TIGHT. You don't want it rattling around on you back there. Of course then a little bit of rust will cause the telescoping tubes to seize tight.

For sure you'd want the extension to be STOUT. Big beefy square tubing, but also be aware that with the stout come the pounds. It will definitely be heavier than a receiver extension, that's for sure.

Didn't miss it... just haven't designed it for him. How could it possibly not be legal? I fail to follow that line of thought.

Two pins? What is the difference between a standard receiver which has one pin and an extension? It's still a pin in shear...is the stress on the extension pin greater than the receiver?

Lot's of ways to have a tight fitting, easily adjustable tube. Every boom truck/dump trailer/etc has tight fitting extensions that slide fairly easily.

In agreement that extensions add pounds. Which brings us back to the actual construction of the trailer to start with. I don't think just any trailer can be easily stretched. Someone mentioned dump trailers and their extensions. Difference being, they have very little tongue weight. The load sits on the axles, so stretching one out is a little different, even 20 + feet.